Radiation therapy facilities, especially those involving high energy X radiation or neutron radiation, require particularly thick walls, doors, and barriers. Particle accelerators, such as linear particle accelerators, use electromagnetic fields to propel charged particles, such as electrons, protons, or ions, at high speeds along defined beams. Due to radiation from particle accelerators, particle facilities must be designed and constructed to provide adequate shielding.
Known radiation therapy facilities are generally constructed as a room housing the source of radiation, with concrete walls, ceilings, and floors that can reach thicknesses of up to 15 feet. In addition, a maze entry is usually used to provide a wing wall to capture scatter radiation. The entrance to a maze entry or direct entry radiation therapy room can include at least one shielded door to further prevent radiation leakage outside of the room. The shielded door for a radiation therapy room can be constructed as a hinged door having a very thick core, for example 20 inches thick, to provide sufficient shielding. Known shielded doors are also extremely heavy, typically 10,000-20,000 lbs for radiation therapy rooms, and cannot be opened and closed quickly. The time that it takes to open and close a hinged shielded door is especially important in radiation therapy rooms where an operator may need to enter and exit the room repeatedly to make adjustments. For example, in medical applications, several rounds of low energy radiation may be used for diagnostic purposes and patient positioning before treating the patient's tumor with the high energy radiation. After each round of low energy radiation, the operator must either progress down a very long maze corridor leading to the treatment room or alternatively wait for the shielded door to fully open before entering the treatment room to make adjustments to the patient, and then wait for the shielded door to fully close again before starting the next round of low energy radiation testing or high energy radiation treatment. This process can be very time consuming and tiring to the patient.
Bi-parting sliding doors typically permit shorter opening and closing times compared to hinged doors. Because existing bi-parting sliding doors have a relatively linear leading edge at the seam between both doors, they lack the necessary seal required to prevent radiation leakage. One known method to reduce radiation leakage is to equip one of the bi-parting doors with an astragal at its leading edge to cover the seam between the doors.
The increased speed of heavy radiation shielded doors introduces additional safety concerns especially when objects obstruct the closing path of the sliding doors.
A need exists for a sliding door for radiation therapy rooms that provides a sufficient seal to eliminate radiation leakage and improved safety when closing.